1. Field of the Invention
The present invention relates to a developing cartridge and an image forming apparatus using the same.
2. Description of the Related Art
As for conventional image forming apparatuses such as copying machines and laser printers which employ electrophotographic systems, it has been a trend that toner cartridges or developing cartridges can be replaced by users themselves for improvement of convenience for the users. While such cartridges are usually replaced when the toner runs out, many cartridges are to be replaced when the cumulative number of printed sheets or the cumulative time of use reaches a predetermined level, because image quality is reduced as developers, components, or the like deteriorate.
For example, such a cartridge is provided with a fuse and a counter that records usage of the cartridge. The fuse is fused to reset the counter when the cartridge is initially mounted on an image forming apparatus (hereinafter, may be also referred to as initial detection). The counter instructs a user to replace the cartridge when the cartridge reaches time for replacement (see, for example, Japanese Unexamined Patent Publication No. HEI 5(1993)-249777).
A sealing member is usually used for the cartridge to prevent the toner or developer from leaking from the opening of the cartridge due to vibration during transportation of the cartridge. However, some users carelessly mount such a cartridge on the image forming apparatus without removing the sealing member, which causes a malfunction to the cartridge, the developing cartridge, or the image forming apparatus.